The decline in the diversity and biomass of arthropods, insects in particular, in agricultural landscapes poses a major challenge to agriculture. There is little evidence about the effect of introducing grain legumes into cropping systems on this group of organisms. In a review of the international literature, we found that, except for soybean, there is almost no information on the impact of grain legumes on arthropod diversity and activity density. A quantitative analysis of the available information on soybean showed that soybean crops have a greater activity density and species richness of arthropods compared to other arable crops such as maize and wheat. Against the background of the critical state of agroecosystem biodiversity, we conclude that the introduction of soybean into cropping systems otherwise dominated by cereals is unlikely to cause a further decline in arthropods with the likelihood of some gains.